In a resignation statement, the former Arizona governor called heading DHS “the highlight of my professional career.”

“We have worked together to minimize threats of all kinds to the American public,” she said. “The Department has improved the safety of travelers; implemented smart steps that make our immigration system more fair and focused while deploying record resources to protect our nation’s borders; worked with states to build resiliency and make our nation’s emergency and disaster response capabilities more robust; and partnered with the private sector to improve our cybersecurity.”

Napolitano said she would be “nominated as the next President of the University of California to play a role in educating our nation’s next generation of leaders.”

The Times quoted unnamed officials as saying that the UC regents were set to approve her nomination next week, and that she would take the position in September.

“While some may consider her to be an unconventional choice, Secretary Napolitano is without a doubt the right person at the right time to lead this incredible university," the Times quoted Sherry Lansing, the regent and former film industry executive who headed the search committee, as saying in a statement being released Friday. "She will bring fresh eyes and a new sensibility -- not only to UC, but to all of California. She will stand as a vigorous advocate for faculty, students and staff at a time when great changes in our state, and across the globe, are presenting as many opportunities as challenges.”

Obama praised Napolitano’s “outstanding work” in his Cabinet in a written statement. He gave no hint of whom he might consider nominating to succeed her.

“She’s worked around the clock to respond to natural disasters, from the Joplin tornado to Hurricane Sandy, helping Americans recover and rebuild,” Obama said. “Janet has led my administration’s effort to secure our borders, deploying a historic number of resources, while also taking steps to make our immigration system fairer and more consistent with our values.”